“It’s been good,’’ said Celtics coach Doc Rivers before his team hosted the Atlanta Hawks on Friday night at the TD Garden. “We just keep running it. We don’t do it in long periods. We have the last couple (of games).

“A lot of that has been situational. Kevin (Garnett) was in foul trouble. Jet (Jason Terry) was struggling defending, so we were trying to hide them in some ways.

“A lot of times, it’s just a team scores five times in a row, throw zone on them twice and get back to man just to throw them out of rhythm.’’

Rivers said the Celtics have been working on zone defense since training camp and go over an aspect of it during practices, shootarounds and walkthroughs.

“We confuse them sometimes,’’ said guard Avery Bradley. “I feel like we’ve been getting better at our zone defense every single game. We talk the whole time on the floor.

“Kevin’s our defensive leader and tells everybody where to go. Paul (Pierce) helps me out personally. He talks the whole time and I feel like that’s what helps our zone and man-to-man defense.

“We’re always talking on the floor. I feel like that’s the best thing in a zone. That’s why sometimes it turns into man with us because we talk and we switch. We might just break off the zone and turn into man. It might confuse the team. I think it’s a good little mix that we do.’’

Son’s season over: Rivers’ son, Austin, a rookie with the New Orleans Hornets, will miss the remainder of the season after fracturing his right hand.

The guard was injured after making a steal early in the second quarter from Antawn Jamison of the Los Angeles Lakers on Wednesday night. Rivers, who finished out the half, will undergo surgery early next week.

Page 2 of 2 - Rivers had struggled early in the season and had his playing time reduced, but his minutes had been on the rise in recent days, and he averaged 6.2 points in 61 games.

“It’s a bummer,’’ said Doc Rivers. “I thought he was playing great over the last six weeks. He was playing terrific. They were keeping him on the floor.

“The good part about it is now he knows he can play and he knows he can play well. He was 5-for-5 before he got injured and took one shot with a broken hand, which tells you his mentality right there. He thought he could make it.

“It happens and it’s late enough in the year and they’re not going to the playoffs that I just think it was important for him to get it going before. If that hadn’t happened, then it would have been a tough injury. Now it’s just another injury.’’

On the road: The Celtics play their next two games away from the Garden, traveling to Oklahoma City for a national TV date with the Thunder on Sunday afternoon and they will be at Charlotte on Tuesday. … The 10-day contracts of D.J. White and Shavlik Randolph expire today and Sunday, respectively, but Rivers isn’t sure what will happen with them. … Garnett received a standing ovation in the first quarter when it was announced that he moved into 10th place on the NBA’s all-time list for rebounds earlier this week.